Freud, the father of psychoanalytic theory, proposed that every individual's personality is the product of a struggle among three interacting forces- the id, the ego, and the superego.
Freud theorized that there are four universal stages of psycho-sexual development which are decisive in the formation of personality. These stages are; oral, anal, phallic and genital. The first three stages of development extend from birth to five years and are called prudential stages since the genital zones of the body have not attained a dominant role in personality development.